Cellulose-nitrate composition



SM one,

I UNITED STATES PATENT OFFICE.

HANS T. CLARKE, OI ROCHESTER, NEW

YORK, ASSIGNOR T0 EASTMAN KODAK COI- PANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

CELLULOSE-NITRATE COMPOSITION.

No Drawing.

To all whom it may concern:

Be it known that I, HANS T. CLARKE, a subject of the King of Great Britain, residing at Rochester, 1n the count of Monroe and State of New York, have invented certain new and useful Improvements in Cellulose-Nitrate Compositions, of which the following is a full, clear, and exact specification.

This invention relates to a new composition of matter and a method of making the same, in which cellulose nitrate is combined or mixed with other substances, so that the resulting product can be advantageously used in the plastic and analogous arts, such, for instance, as sheet or film manufacture and varnish manufacture.

One object is to produce a composition which may be made into permanently transparent, strong and flexible sheets or film of desired thinness that are substantially waterproof, are unaffected by ordinary photographic fluids'and possess the desired properties of a support for sensitive photographic coatings. Another object of my invention is to produce a composition of matter capable of easy manipulation in the plastic and film making or varnish making arts; which will not injure or be injured by the substances with which it is associated during manufacture, storage, or use. Still another object of my invention is to provide a process for compounding such composition of matter. Further objects will hereinafter appear.

I have discovered that a composition of matter having the desirable qualities hereinabove enumerated can be obtained by mlxing or compounding cellulose nitrate with simple alkyl sulfones which are only slightly volatile or non-volatile at ordinary tempera.- tures. By simple alkyl sulfones I- mean substances of the type indicated by the following formulae in which A and B repre- There are noted, forexample, normal dibut 1 sulfone, diisobutyl sulfone, d methyl diethyl sulfone, normal dlpropyl sulfone, diisopropyl sulfone diisoamyl sulfone, methyl ethyl sulfone, diheptyl sulfone sent alkyl groups:

Specification of Letters Patent.

and ethylisoamyl sulfone. These may, of course, be mixed as well as used singly, and the degree of purity will depend upon the purposes to which the plastlc composition is to be put. These substances vary as regards their boiling points, tendencies to volatilize, and solubilities with respect to water; and so are useful in varying ways in different branches of the plastic arts. These sulfones all have boiling points above 200 C. and are very stable. The latter property is particularly essential in the photographic art where the liberation of breakdown sulfur products might impair the light-sensitive coating. Their properties appear in various degrees in their homologues and derivatives. The compounding is best performed b using asolvent com mon to both the co lulose nitrate and the sulfone.

For flexible film and varnish manufacture, the simple alkyl sulfone should be so nearly non-volatile that its loss during the desired life of the film will not be suflicient to make the latter unserviceable. They are less combustible than cellulose nitrate and impart this quality to a very useful degree to the com ound.

As a typ cal useful example of the dialkyl sulfones, which may be employed in exercising my invention, the normal dibutyl sulfone 1s selected. It is a white solid at ordinary temperatures and its boiling point is above 250 C., so that its volatility when compounded with nitrocellulose is practically m'l. It is practically insoluble in water and very stable.

In carrying out one illustration of my in vention, I incorporate in 20 to 30 parts of an acetone and methyl alcohol mixture the followingingredients: cellulose nitrate 3 to 6 parts, (say, for instance, 5 parts) normal dibutyl sulfone part to 10 parts. The acebutyrate, etc.

- Patented Mar.'8, 1921. Application filed March 17, 1919. Serial No. 283,228.

trate and sulfone, together with the additional high boiling softener if the latter is used, is very flexible, transparent, and uniform, so that it can be used for any usual or preferred purpose. It is practically waterproof and unaffected by ordinary photographic chemicals. The sulfones are so stable that they do no. in any appreciable degree liberate products which injure metal or other parts with which they come in contact during manufacture; and moreover they do not chemically react with or injure the other bodies that are associated with them in the solution or the completed film.

While I have hereinabove disclosed certain compositions and processes by way of example, my invention is not limited thereto nor to the proportions given therein, as the proportions maybe varied from those given and equivalent substances may be substituted without departing from the principle of my invention as defined in theappended claims. w

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A transparent composition of matter comprising cellulose nit-rate and a simple dialkyl sulfone.

2. A composition of matter comprising cellulose nitrate and a dibutyl sulfone.

3; A' flowable film-forming composition of matter comprising cellulose nitrate, a simple dialkyl sulfone, and a. solvent common to both.

4. A composition of matter comprising cellulose nitrate, a dibutyl .sulfone, and a solvent common to both.

5. A flowable film-forming composition of matter comprising cellulose nitrate, a simple dialkyl sulfone anda solvent containing acetone and methyl alcohol.

(3. A composition of matter comprising cellulose nitrate, a dibutyl sulfone and a solvent containing acetone and methyl alcohol.

7. A composition of matter comprising cellulose nitrate, a simple dialkyl sulfone, a solvent common to both, and an organic body of only slight volatility which enhances the plasticity and fiexibilityof the composition. f

8. A composition of matter comprising acetone 10 to 20 parts, methyl alcohol 10 to 20 parts, cellulose nitrate 3 to 6. parts, (libutyl sulfone to 10 parts.

9. As an article of manufacture, a tough flexible sheet of deposited or flowed cellulose nitratecontaining a simple dialkyl sulfone.

10. As an article of manufacture, a sheet of deposited or flowed cellulose nitrate containing a dibutyl sulfone.

11. As an article of manufacture, a sheet of deposited or flowed cellulose nitrate containing a simple dialkyl sulfone and an organic body of slight volatility which enhances the flexibility of the sheet.

12. Theprocess of making a composition of matter which consists in combining cellulose nitrate and a simple dialkyl sulfone in a solvent common to both.

13. The process of making a composition of matter which consists in combining cellulose nitrate and a dibutyl sulfone by the use of a solvent containing acetone and methyl alcohol.

Signed at Rochester, New York, this 15th H day of March 1919.

HANS T. CLARKE. 

